1. Technical Field
The present application relates to method of testing, determining, and adjusting a final closing torque of a beverage bottle or container closing machine and an apparatus for performing the method.
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
Beverages and other liquid products are commonly stored in containers or bottles such as plastic bottles, blow-molded bottles, or polyethylene terephthalate (PET) bottles. Such bottles often have threaded mouth portions onto which a threaded screw cap or closure is placed to close the bottle. These screw caps are usually placed on the bottles by an automated or motorized closing machine located downstream of a filling machine. Especially with plastic bottles, it is desirable to screw the screw caps onto the bottles with sufficient force or torque to close and seal the bottle, but without over tightening the bottle such that the bottle is damaged or is very difficult to open by a consumer.
For containers, for instance, bottles, such as plastic bottles, blow-molded bottles, or polyethylene terephthalate (PET) bottles, that are closed with screw caps, it is desired that the consumer should exert, for opening of a bottle, a certain amount of force, i.e. the maximum opening-torque for the opening of such closures is expended; in other words, such screw caps should not be tightened at the bottle mouth to present an uncomfortable opening of a bottle. However, it is also desired that a screw cap is screwed tightly enough onto the respective container in order so as to effectuate sealing of the bottle by closing of the screw cap on a bottle and, for instance, preclude the escape of contents materials, e.g., carbonic acid, or carbon dioxide when in water, but also to preclude the ingress of foreign matter, to reliably restrict or minimize introduction, for instance, of injurious germs into the container as originally closed during the bottle filling operation.
In other words, some bottles are closed with screw caps or screw closures. To open a bottle with a screw cap, the consumer exerts a force or opening-torque to remove the screw cap. Bottles should be sufficiently closed to restrict or minimize bottle contents from leaking or escaping, while also being sufficiently closed to restrict or minimize dangerous foreign matter from entering the bottles. However, bottles should not be closed so tightly that the consumer exerts an uncomfortable amount of opening force or opening-torque to open the bottle.
On account of the qualities or characteristics of the combination comprising a screw cap and a container, and due to the construction and the control of the motorized units or arrangements for closing of the containers, the desired force, hereinafter also referred to as torque or opening-torque that is desired for a subsequent opening of a container, is determined by the maximum force or torque (herein below also referred to as closing final-torque) upon screwing of a screw cap onto a container, i.e. during closing of the container upon filling.
So as to accommodate the preceding requirements concerning maintenance of operational production assuredness and user-friendliness, it is necessary or desired to set the closing-force desired to properly secure the cap with a corresponding maximum closing final-torque, or force. Furthermore, it is also desirable to hold the corresponding opening-torque of all or most closed containers within narrow tolerance limits, i.e. the force a user should apply to unscrew a cap from a bottle.
Some closing machines empirically set the closing final-torque by use of motorized closing units, namely, for instance, by the fact that in a setting, tuning, or equilibration phase, several containers are closed by the pertaining closing unit that is to be tuned, and such closed containers are again manually opened afterwards. On this occasion, the opening-torque is determined using a suitable measuring instrument (e.g., a torque meter). Then, through a comparison of the set-point value of the opening-torque with the measured actual value of this force or torque, the respective screw unit or closing unit is set as desired, also taking into consideration the measured values of further tuning investigations. It is of possible disadvantage in this method, among other things, that the manual measurements for this setting or tuning may require trained staff capable to utilize the measured parameters or values for conclusions pertaining to the final setting of the respective closing unit. It is disadvantageous, furthermore, that the measuring results that are taken during the course of the tuning or equilibration phase are rather inexact during opening of the containers, namely because of the manual opening movement which basically can not be carried out with a constant movement, or consistently, or, respectively, continuously.